Oscillating armature motor



March 22, 1966 R. GUICHARD OSCILLA'TING ARMATURE MOTOR Filed April 8.,1965 a//l/l v INVENTOR. ROLAND GUICHARD AGENT hand of the user of theapparatus.

United States Patent O 2 claims. (el. 31o- 37) The invention relates toa motor comprising an oscillating armature for driving tools,particularly for driving the cutting members of hair clippers and/ orshaving apparatus.

In such apparatus the cutting members are moved in an oscillatory mannerbehind one or more combs or shear plates.

The invention is characterized in that the driving connection betweenthe armature and the tool is solely formed by an elastic element.

In a known apparatus the elastic part, which guides or controls themoving parts (for instance the cutting members and the oscillatin-garmature) is connected with the housing of the apparatus in `a rigidmanner, so that the oscillations of the armature are transferred to theWith such constructions the moving parts of the motor and the cuttingmembers perform such oscillatory motions that their masses and theoscillations thus produced reinforce each other.

The invention has particularly for its object to provide such astructure of these apparatus that they can better fulfill therequirements of practice, while the aforesaid disadvantages are avoided.

The elastic element may be formed by a leaf spring, one end of which isrigidly secured to the armature, while between its ends the leaf springis supported between two opposite points of support so that it isdisplaceable in its longitudinal direction. The dimensions of said leafspring are preferably chosen so that it oscillates in its resonancefrequency.

The end of the elastic element, which drives the tool, may also beprovided with one or more fingers, which are adapted to tilt and toslide in one or more slots provided in the tool.

The invention will be described more fully with reference to theaccompanying drawing, which shows one embodiment of the invention.

FIG. l is a longitudinal sectional view of an apparatus comprising amotor according to the invention.

FIG. 2 is a longitudinal sectional view of a further apparatus accordingto the invention.

The apparatus shown in FIG. l is a dry shaving apparatus, the shearplate 13 of which, behind which the cutting member 8 is adapted to move,constitutes one end of a largely cylindrical or prismatic housing.

The cutting member 8 has two projections 8a, which form together a slot,in which a finger 9 is adapted to tilt and to slide. This finger 9 issecured to an elastic or resilient element 6 by casting or by othermeans; this elastic element has the form of a leaf spring, shown on itsnarrow side, which spring constitutes the sole connection with theoscillating armature 4 of the motor 1.

This armature of magnetic material opens and closes during itsoscillations the magnetic circuit formed by it together with thestationary part 2, the stator of the motor 1. This stator is formed by aU-shaped electromagnet, which is excited by alternating current passingthrough the coils 3, so that per period of the said alternating currentthe armature 4 fulfills a complete oscillation about its axis 5. Thusthe leaf spring 6 is set oscillating. On either side of two oppositerollers 10 3,242,357 Patented Mar. 22, 1966 the leaf spring 6 is held soas to be slidable in its longitudinal direction; these rollers are heldby two supports 11, which are rigidly secured to the housing 12, so thatan oscillation node is produced. The leaf spring 6, with the mass of thearmature 4 at one end and that of the finger 9 and the cutting member 8at the other end, constitutes an oscillatory system with its ownfrequency, which depends upon the rigidity of the leaf spring 6 and themagnitude of the moving masses, since this oscillation frequency isdetermined by the frequency of the leaf spring, connected with thearmature, and the oscillation frequency of the leaf spring, connectedwith the cutting members. The magnitude of the amplitude of the armatureand that of the amplitude of the cutting members can be adjustedrelatively to each other to the most favourable values by a suitablechoice of the mass of each of these elements. In order to obtain the.best results, the resultant frequency mustbe equal or substantiallyequal to the frequency of the magnetic forces due to the alternatingcurrent passing through the coils 3. The rigidity ofthe leaf spring 6 isdetermined by its size and shape, while the place of the node isdetermined by the two rollers 10 and the magnitude of the moving masses.

From FIGURE 1 it will be seen that the leaf spring 6 preformstransversal oscillations (see the broken lines) on either side of theaxis 5 associated with its rest position, the antinodes occurringbetween said axis 5 and the rollers 10 and at the end, where the finger9 is fastened. In order to permit distance variations between the axis 5and the finger 9 due to the bending of the leaf spring in the proximityIof the antinodes, the said leaf spring 6 must be capable of slidingbetween the rollers 10, since it is rigidly secured to the armature 4.To this end the leaf spring is laterally supported so as to be slightlyresilient by means of the two rollers 10 of elastic material. Theelasticity of these two rollers is chosen so that the leaf spring 6 canbe bent and can slide slightly in its longitudinal direction.

FIG. 2 shows a different embodiment of an apparatus according to theinvention, in which the cutting faces forming the shear plates form partof the sides of the housing, which has an elongated shape.

1n FIGURE 2 corresponding parts are designated by the same referencenumerals as in FIG. 1.

The moving part 16, secured to the leaf spring 6 similarly to the finger9, has at its end two identical fingers, which are capable of tiltingand sliding in slots provided to this end in the cutting members 8 and14.

The additional cutting member 14, which is associated with the shearplate 15 and also serves for shaving, could also be used for hairclipping.

It will be obvious that the cutting members V8 and 14 are driven by themoving part 16 in the longitudinal directions of their respective shearplates by the oscillatory movement of the leaf spring 6, produced by themotor 1. In this embodiment the moving masses can be completelybalanced, since the assembly of the cutting members 8 and 14 and themoving part 16 constitute a mass which rotates about a point between therollers 10 in a direc tion opposite the rotation of the mass of thearmature 4 about the axis 5. If the masses are correctly chosen, theapparatus will operate without the oscillations being transferred to theusers hand.

The use of the motor with the oscillating armature according to theinvention is not restricted to the aforesaid apparatus. Such a motor mayalso be used for example in small pumps and in oscillating brushes.

What is claimed is:

1. A motor for an apparatus comprising an oscillating armature, aresilient element solely connecting said oscillating aramture with saidapparatus, said resilient ele- ICC ment constituting a leaf springhaving one end thereof rigidly secured to said armature, and meansslidably supporting said leaf spring between its ends at two oppositepoints whereby said leaf spring can slide therein in a direction alongits longitudinal axis.

2. A moror for an electric shaver, said shaver being provided with aslot, comprising an oscillating armature, a resilient `element solelyconnecting said socillating armature with said electric shaver, at leastone nger on one end of said resilient element adapted to t in said slotand tilt and slide therein, said resilient element constituting a leafspring having one end thereof rigidly secured to said armature, andmeans slidably supporting said leaf spring between its ends at twoopposite points whereby said leaf spring can slide therein in adirection along its longitudinal axis.

References Cited by the Examiner UNITED STATES PATENTS 2,013,229 9/1935Audis 310--29 X 2,967,253 1/1961 Wahl 3l0-29 3,105,163 9/1963 CampS10-29 0 oRrs L. RADER, Primary Examiner.

MILTON O. HIRSHFIELD, Examiner.

CYRIL W. DAWSON, Assistant Examiner.

2. A MOTOR FOR AN ELECTRIC SHAVER, SAID SHAVER BEING PROVIDED WITH ASLOT, COMPRISING AN OSCILLATING ARMATURE, A RESILIENT ELEMENT SOLELYCONNECTING SAID OSCILLATING ARMATURE WITH SAID ELECTRIC SHAVER, AT LEASTONE FINGER ON ONE END OF SAID RESILIENT ELEMENT ADAPTED TO FIT IN SAIDSLOT AND TILT AND SLIDE THEREIN, SAID RESILIENT ELEMENT CONSTITUTING ALEAF SPRING HAVING ONE END THEREOF RIGIDLY SECURED TO SAID ARMATURE, ANDMEANS SLIDABLY SUPPORTING SAID LEAF SPRING BETWEEN ITS ENDS AT TWOOPPOSITE POINTS WHEREBY SAID LEAF SPRING CAN SLIDE THEREIN IN ADIRECTION ALONG ITS LONGITUDINAL AXIS.